(Bloomberg) —

A unit of Guinea’s military seized power and suspended the constitution, destabilizing a key source of the raw material used to make aluminum.

The head of special forces in the West African nation, Colonel Mamady Doumbouya, announced the takeover on state television on Sunday, imposed a curfew of 8 p.m. local time and urged the armed forces to back him. The action was taken to address financial mismanagement and corruption in Guinea under President Alpha Conde, he said, adding that the deposed leader is safe and has been in contact with his doctors.

“If you see the condition of our roads, of our hospitals, you realize that it is time for us to wake up,” Doumbouya said. “We are going to initiate a national consultation to open an inclusive and peaceful transition.”

Guinea vies with Australia as China’s largest supplier of bauxite, which is used to make alumina and eventually aluminum. The country shipped 82.4 million tons of the mineral globally last year, according to government data. Much of that went to China, which is the world’s biggest aluminum-consuming country.

Aluminium prices on the London Metal Exchange rose as much as 1.8% to $2,775.50 a ton, the highest since May 2011, before trading at $2,749. In China, futures jumped as much as 3.4% to the highest since 2006. Chinese aluminum stocks also rallied, with Aluminum Corp. of China shares up as much as 10% in Hong Kong.

The military takeover “might have a speculative impact on the price of aluminum but will have a bigger impact on the alumina price because it’s more immediately exposed to the event,” said Tom Price, head of commodities strategy at Liberum Capital Ltd. “It’s an event which will create a new risk of security to supply.”

Aluminum has jumped about 50% over the past year in London and is near the highest in a decade. Prices have rallied as a global economic recovery from the effects of the pandemic and Chinese output restrictions stoked demand. The energy-intensive aluminum industry has been targeted in China as the government seeks to conserve electricity and curb emissions, while a seasonal power crunch has also dented production.

Companies including United Co. Rusal have invested heavily to extract Guinea’s abundant iron-ore and bauxite reserves. Rio Tinto Group, the world’s largest miner, has been looking at ways to exploit Simandou, the biggest undeveloped iron-ore deposit. Johannesburg-based AngloGold Ashanti Ltd. owns the Siguiri gold mine in Guinea, its only asset in the country.

Rusal’s spokesman declined to comment on the military takeover, but said it could have an impact on output. Guinea accounted for about 9% of the alumina produced by Rusal in the first half of 2021, according to the company.

The U.S. State Department condemned the coup and called for a peaceful national dialogue to “enable a peaceful and democratic way forward for Guinea to realize its full potential.” United Nations Secretary-General Antonio Guterres also blasted the military takeover.

Leaders of two African blocs have pushed for the release of Guinea’s president. Leaders of the Economic Community of West African States also threatened sanctions against Guinea, Chairman Nana Akufo-Addo said in a statement.

The regional political and economic body “condemns with the greatest firmness, and also demands a return to constitutional order,” Akufo-Addo, who’s also Ghana’s president, added.

The African Union also called for its Peace and Security Council to meet urgently over the matter.

Doumbouya’s TV appearance bore a resemblance to a similar scene in August 2020, when a Malian junta removed President Ibrahim Keita after blaming him for the country’s socio-economic problems. And in April, Chad’s army seized power after the death of President Idriss Deby.

The military takeover in Guinea on Sunday came hours after heavy gunfire erupted near the presidential palace in the capital, Conakry, in the morning.

Conde’s government said in a statement before Doumbouya’s announcement that the presidential guard, backed by the nation’s security forces, had repulsed the attack by the “insurgents” and called for calm.

Conde, 83, was sworn in December for a third term in office, vowing to fight corruption. Initially hailed when he came to power in 2010 for ushering in democratic rule, he was allowed to run for a controversial third term last year after a referendum, backed by Russia, led to a change in the constitution.

A former educator, Conde has increasingly cracked down on opponents as opposition against his rule has grown.

(Adds aluminium price in fifth paragraph)

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